var getIntersectionNode = function(headA, headB) {
  let n1 = headA
  let n2 = headB
  while (n1 !== n2) {
      if(n1 == null) {
          n1 = headB
      }else {
          n1 = n1.next
      }
      if(n2 == null) {
          n2 = headA
      }else {
          n2 = n2.next
      }
   }
   return n1

};